Two more people have been arrested in relation to the alleged kidnapping and murder of Sydney grandfather Chris Baghsarian last month.

Detectives and tactical operations officers executed a search warrant in the Sydney suburb of Seven Hills at about 6.30am on Wednesday morning, New South Wales police said in a statement.

They arrested a man and a woman, both aged 23, at the address. The pair were taken to Riverstone and Blacktown police stations to assist with inquiries.

Police allege Baghsarian, 85, was kidnapped from his North Ryde home on 13 February in a case of mistaken identity. His body was dumped near a golf club at Pitt Town days later, police allege, but was not found until 24 February.

The new arrests come after two men – Daniel Stevens, 24, and Gerard Andrews, 29 – were charged in February with murder and taking or detaining in company with intent to ransom, occasioning actual bodily harm.

Earlier this month, police released CCTV footage of three more men they wanted to speak to in relation to the alleged kidnapping and murder.

The footage showed three men walking towards what police alleged was the kidnappers’ “stronghold” at Dural, in north-western Sydney, on the night Baghsarian went missing, and a blue Hyundai sedan with a missing hubcap that police believe visited the house where Baghsarian was held captive.

The investigation continues.